Transcript MAP65 21st Century EME

Moonbounce
“HowTo”
K1JT – WA3BZT – K2TXB
WB2RVX – W3CMP – W3HMS
PackRats 21 October, 2010
Overview
K1JT
– EME fundamentals
WA3BZT – antenna, preamp, feedline, …
K2TXB – “back end” setup; making QSOs
WB2RVX – EME and contesting
W3CMP – portable EME
W3HMS – 1296 EME with a 3m dish
EME Basics
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It’s hard… so it’s fun!
Path loss: -240 to -290 dB
Best possible Rx NF
High power, big antennas ???
Which band(s)… and why?
Sky Map: Galactic Noise, 144 MHz
Spectrum
f -2.6
Tsys – the Fundamental Limit
50
144
10
432
1.3
3.4
Pnoise = kTB
Which Band ?
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50: galactic noise → high Tsys
144: most activity, easiest
432: smaller antennas; low Tsys
1296: 10-12ft dish “enough”
2.3, 3.4: SSPAs; activity gaining
5.7, 10: TWT amplifiers
Desirable Equipment
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Preamp at antenna
Sequencer to protect preamp
Low-loss feedline
144, 432: polarization diversity
Antenna positioning in Az, El
Computer-rig interface
Typical Requirements, CW EME
(BW = 50 Hz
S/N = 3 dB)
Frequency Ant
(MHz)
Type
G
(dBi)
HPBW
(deg)
TxPwr
(W)
50
144
432
1296
2304
3456
5760
10368
19.7
21.0
25.0
29.5
34.5
34.8
39.2
44.3
18.8
15.4
10.5
5.5
3.1
3.0
1.8
1.0
1200
500
250
160
60
120
60
25
4×12 m
4×6 m
4×6 m
3m
3m
2m
2m
2m
 But: JT65 needs 10 – 15 dB less 
KL7UW – 4×6m yagis, 144 MHz
VA7MM – 3m dish, 1296 MHz
N4MW – 2.6m dish
10 GHz Xvrtr
TWT PA
Portable/QRP EME, DXpeditions
TF/DL3OCH
Iceland
Moon
3A/DL3OCH
Monte Carlo
DL3OCH: 1296 MHz EME station
Does EME Really Work?
K1JT on 144 MHz
• WAS = 50
• DXCC = 97
• WAZ = 34
• VUCC = 543
• 2m grids, VHF SS = 76
• EME “initials” = 638
• EME QSOs ~ 3000
Putting it all together
• Finding and tracking the Moon
• Good times of the month
• Measuring Sun noise
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Hearing/detecting your own echo
Computer-to-rig interface
The “loggers”
Making QSOs